Apparatus for regulating yarn tension



Sept. 1952- P. J. CAMPBELL 2,610,813

APPARATUS FOR REGULATING YARN TENSION Filed March 12, 1946 4Sheets-Sheet 1 [NVENTOIZ 1900/ J. Campbe ZMW Sept. 16', 1952 P. J.CAMPBELL" APPARATUS FOR REGULATING YARN TENSION 4 Sheets-Sheet 2 FiledMarch 12, 1946 INVENTOQ Sept. 16, 1952 P. J. CAMPBELL APPARATUS FORREGULATING YARN TENSION 4 Sheets-Sheet 3 Filed March 12, 1946 I/NVENTOIZC J. 5 m 6 V AC E Z r 1 a V x mm m 4 u M o m m R 3 Z 2 H I N n H1 iv 14. 4. .Wnm Fu Jr H v 0 7x 1 0% 7 m n 2 r 4 sq 5% 9 B.

a o bcl/ By Sept. 16, 1952 Filed March 12, 1946 P. J. CAMPBELL APPARATUSFOR REGULATING YARN TENSION 4 Sheets-Sheet 4 PRESSURE GAUGE n RELIEF//26 I VALVE I24 /22. 1/8 20 n/ FAowRassuRELJneuEFLl AIR UAIR l.

- REGULATOR m VALVE n com nzssognnuznr INVENTOR Pau/ J. Camp be PatentedSept. 16, 1952 APPARATU S FOR REGULATING YARN TENSION Paul J. Campbell,Berlin,v Conn assignor, by mesneassignments, to Raymond EngineeringLaboratory, Inc.,- Middletown, Conn., a corporation of ConnecticutApplication March 12, 1946, Serial No. 653,850

The invention relates particularly to an appa-- ratus for regulating thetension in one'or more moving strands of material such as yarn, as forinstance in one or more such strands being wound onto a rotating'beam orequivalent device and being-unwound from oneor more packages;-

The word yarn will herein be used in a generic sense to include not onlymaterial oi thetypes commonly designated as yarn, but also other.materials as to which there may be necessityfor.

winding under controlled tension. I

Oneof' the general objects of the invention is to provide a regulatorunit for use with a single strand of yarn and'having improved means formaintaining the tension in the yarn strand substantially constant as itleaves the unit. Constant tension is maintained notwithstandingvariations in the tension in the yarn as it moves to the unit andnotwithstanding variations in the operating conditions, such asvariations in the size and texture of the yarn and variations inhumidity. Othervariations in the tension in the yarn passing to theregulator'unit may be due'to the unwinding operation, suchfor instanceas the tendency of'the unwinding thread to stick between the adjacentwound coils of the package.

A more specific object of the invention is to provide a regulator unitwherein the required.

regulation of the tension-to maintain it constant is effected by fluidactuated means and more parcularly by pneumatic means.

A further more specific object of the invention is to provide aregulator unit having a means, such as a friction means, forresistingthe movement of the yarn so as to provide tension therein,

and having fluid actuated means, such as pneumatic means, for varyingthe resistance applied to the yarn by the resisting means, the action ofthe said fluid actuated means being controlled by the tension of theyarn after passing the said resisting means.

A still further more specific object of the invention is to provide aregulator unit having a means, such as a friction means, which resiststhe movement of the yarn so as to provide tension therein, and which isbodily movable as the result of variations in the said tension, andhaving fluid actuated means, such as pneumatic means, for

varying the resistance applied to the yarn by the resisting means, thesaid resistance being varied in accordance with the said bodily movementof the resisting means. v

A still further specific object of the invention is to provide aregulator unit wherein the tension in the moving yarn is maintainednormally con 41 Claims. (01. 242-150) stant, but wherein the amount ofthe said nor.-' mally constant tension may be controlled and adjusted byfluid actuated means, such as pneumatic means.

I Another general object of the invention is to provide an apparatuscomprising a plurality of similar regulator units each having meansadapted to control the amount of tension in its own strand of yarn andtomaintain-such tension constant, and also comprising a common fluidpressure actuated means for providing uniform and constant tension inthe strands of yarn at all of the units and for uniformly varying theamount of the said uniform and constant tension.

Other objects of the invention will be apparent from the followingspecification and claims.

In the drawings I have shown in detail a preferred embodiment of theinvention and such embodimentwill be full described, but it will beunderstood that various changes may be made from the construction shownand described and that the drawings and description are not to beconstrued as defining or limiting the scope of the invention, the claimsforminga-part of this specification being relied upon for that purpose.

Of the drawings,

- Fig. 1 is a plan view of one of theunits' of the apparatus with aportion broken away. i

Fig. 2 is a front view of the unit shown in Fig. 1.

Fig. 3 is a side view of the unit shown in Fig. l with a portion brokenaway.

,Fig. 4 is a fragmentary side view similar to Fig. 3 but showing thefriction members in engagement with a strand of yarn and also showingthe primary tension means which is omitted in Figs. 1 and 3.

Fig. 5 is an enlarged front view of the unit with the front coverremoved and with the upper portion shown in vertical section along theline 5-5 of Fig. 3.

Fig. 6 is a fragmentary view similar to Fig. 5 but showing the frictionmembersin engagement with a strand of yarn. v

Fig. .7 is an enlarged vertical sectional view taken along the line 1-1of Fig. 5.

Fig. 8 is a diagrammatic view of an apparatus embodying the inventionand including a plurality of the units shown in detail in Figs. 1 to 7.

The general objects of the invention and some of the more specificobjects thereof have been particularly stated. The details of.construction will be -described in detail by reference to the drawings,particularly Figs. 1 to 7 thereof.

A main casing or housing I is provided which carries the various partsof the unit and encloses some of them. The casing has a front cover [2and a top cover [4 which carries some of the parts of the unit. A meansis provided for resisting the movement of the yarn, and this meanspreferably has direct frictional engagement with the yarn and includestwo separate relativel movable friction members. As shown, the frictionmembers are oppositely cupped washers l6 and I8 which are rotatableabout a common verticalaxis, but which may tilt to slightly shift thepositions of their axes as will be more fully explained. A supportingelement 20 is provided for the friction washers l6 and I8, this elementbeingsupported within the housing Ill. The element 20 extends through anopening 2| in the top cover l4, and the washers are located above thesaid cover. Carried by the supporting element 20 is a means for movingthe lower friction washer I8 upward toward the upper friction washer IS.The said means for moving the friction washer I8 is preferably fluidactuated, and as shown, it comprises a piston 22 rigidly secured to thesupporting element 20, the upper portion of which is cylindrical. Thesaid means also comprises a cylinder 24 which surrounds the piston 22,being movable vertically with respect thereto. As shown, the cylinder iswithin the opening 2|.

The cylinder 24 has an upward extending sleeve 26 which surrounds thecylindrical portion of the supporting element, a bearing bushing 28being interposed between the said sleeve and the cylindrical portion ofthe supporting element. The lower friction washer l8 rests directly onthe top surface of the cylinder 24 and is rotatable thereon, the centralaperture in the Washer being substantially larger than the sleeve 26 soas to permit the friction washer to tilt slightly. The upper frictionwasher I6 has an upward projecting portion which loosely fits and isguided by the upper portion 30 of the supporting element 20, whichportion is of reduced diameter. Clearance is provided between the washerl6 and the sleeve 26 so as to permit the washer to tilt slightly. Thesaid portion 30 of the member 20 carries a collar 32, and a frictiondisc 34 is preferably interposed between the collar 32 and the upwardprojecting portion of the friction washer [6.

As shown in Fig. 4 and also in Fig. 6, the moving strand of yarn 36 inwhich the tension is to be regulated passes between the friction washersI6 and I8 causing the said washers to rotate. The said strand of yarnalso engages the sleeve 26 formed as a part of the cylinder 24 and suchengagement causes the sleeve 26 to rotate, the cylinder 24 beingnecessarily also rotated. In order that the cylinder 24 may rotatefreely clearance is provided between the inner surface of the saidcylinder and the outer surface of the piston 22. This clearance is verysmall and is exaggerated in Figs. and 7 of the drawings.

As shown more clearly in Fig. 7, a tube 31 extends through an aperturein the piston 22 and this tube is connected with a flexible tube 38 bymeans of which fluid under pressure can be supplied to the space withinthe cylinder 24 above the piston 22. It will be seen that fluid pressurein the said space will cause the cylinder 24 to move upward and move thefriction washer l8 toward the friction washer [6, thus applying frictionto the strand of yarn 36 moving between the washers as shown in Fig. 6.When the fluid pressure is changed as hereinafter explained, the amountof friction or resistance is correspondingly changed and the saidcylinder and piston therefore constitute means associated with thefriction or resistance means for varying the friction or resistancethereof.

.There are certain important advantages in using air asthe fluid foroperating the cylinder 24 but the invention is not necessarily solimited. However, in view of the advantages of air, and in order tosimplify the description, air will be hereinafter referred to as thefluid being used. It will be apparent that there will be some escape offluid from the interior of the cylinder 24 through the clearanceprovided between the interior surface of the cylinder and the exteriorsurface of the piston. When air is used, the escape of fluid isimmaterial, provided that suitable provision therefor is made as willpresently be described.

The resistance or friction applied to the strand of yarn depends uponthe air pressure in the cylinder and means is provided for varying thesaid air pressure in accordance with the tension in the strand of yarnafter it has passed the said means for applying resistance such asfriction. Various means may be provided for enabling variations in yarntension to cause variations in air pressure, but preferably, the varyingof the air pressure in accordance with Y variations in tension iseffected by permitting the resisting means, that is, the frictionwashers l6 and I 8, to move bodily in accordance with the amount oftension. To this end the supporting element 20 is preferably pivotallysupported within the casing l0, and as shown, the casing carries ahorizontal pin 40 which extends through a bearing sleeve 42 to which thesupporting element 20 is rigidly connected. The sleeve 42 is engaged bya washer 46 held in place by a cotter pin 48. The opening 2| in the topplate is of such size as to permit limited pivotal movement of theelement 20 and of the parts carried thereby. The air tube 38, beingfreely flexible, does not interfere with such pivotal movement. Pivotalmovement of the supporting element 20 in one direction is limited bymeans of an adjustable stop 50 extending through an aperture in a boss52 on the casing ID. The stop is held in adjusted position by means of aset screw 54.

The unit includes a suitable device or means for providing a constantforce for resisting the pivotal movement of the supporting element 20 inthe direction of yarn tension, that is, in the counterclockwisedirection. As concerns certain broader aspects of the invention, thisdevice or means may be widely varied, but preferably and in accordancewith other phases of the invention, the said means is fluid actuated andmay advantageously be pneumatic. While the invention is not necessarilylimited to a pneumatic means, such a means is shown and will bedescribed. There is provided an air chamber 56 formed within a dependingboss 58 on the top cover H of the casing. This chamber is closed at itsinner side by means of a flexible dia phragm 60 having a contact plate62 thereon. The diaphragm is held in place by a frame 64. An air passage66 is provided in the boss 58, this communicating with a rigid tube 68which in turn is connected with a flexible tube or conduit 10. Air underpressure is supplied through the tubes 10 and 68 to the chamber 56, thispressure tending to move the diaphragm 60 in the inward direction, thatis, toward the right, and resisting movement of the said diaphragm in:the opposite or outward direction. Carried bythe supporting element 20aboveitspivotal axis is a contact member 12 which engages the contactplate 62. 'Ihemember .12 is shown as being a screw extending through athreaded aperture in the supporting element. '1

Fig. 6 is similar to a'portion of Fig. 5, but it shows th parts inoperative positions, with the lower friction Washer l8 moved upward byair pressure and engaging thestrandof yarn 36. It will be seen byreference to Fig. 1. that tension in the strand of yarn tends to movethe friction means I8, l8 and the associated partsincluding thesupporting element 20 in the counterclockwise direction, but that suchmovement is resisted by the air. pressure in the chamber 56 acting onthe diaphragm 60. The air pressure in the-chamber 58 is normallyconstant and therefore the extent of movement of the frictionmeans'andof the supportin element is a direct function of the tension in thestrand of yarn. Normally, equilibrium is established between th yarntension tending to move the parts in one direction and the air pressuretending to move the parts in the opposite direction. Any change in yarntension re-f sulting from any cause, such as variations in primarytension ahead of the friction means, or variationsin the size of theyarn or variations in humidity, has a tendency to upset the equilibrium.At the initiation of any such tendency, the action of the friction meansis immediately adjusted to change the tension and restore theequilibrium. Any minor increase in yarn tension causes the parts to movein the counterclockwise direction, and any minor decrease in yarntension allows the parts to be moved in th clockwise direction by theair pressure acting on the diaphragm 60. The said movements resultingfrom increased or decreased yarn tension are utilized to vary thefriction applied to the yarn by the friction means so as to restore theyarn tension to normal, this being done by varying the air pressurewithin the cylinder 24.

shaped conduit member 14 which is connected with another flexible tube16 leading from a source of air under pressure. The T-shaped member ispositioned in an aperture in a boss 18 on the casing I8, being held inplace by a set screw 80. The T-shaped member 14 has a bleed orifice 82,and a portion of the air flowing through moves in the counterclockwisedirection under the influence of increased yarn tension air flows morefreely through the bleed orifice thus reducing the air pressuretransmitted throughthe tube 38 to the cylinder 24. This reduces thepressure applied to the friction washer l8 and correspondingly reducesthe tension in the strand of yarn 36, restoring such tension to normal.When the supporting element moves in th clockwise direction as theresult of decreased yarn tension, air flows less freely through thebleed orifice, thus increasing the air pressure transmitted through thetube 38 to the cylinder 24. This increases the pressure applied to thefriction Washer l8 and correspondingly increases the tension in thestrand of yarn 36, restoring such tension to normal. The

The flexible tube 38 is connected with aT-' net result is that thetension in the strand of yarn. 36 is maintained substantially constant,notwithstanding all factors tending to chang it.. .c r

The amount 'of the, constant tension in the strand of yarn may be variedby varying the'force acting in opposition to the tension in th'eyarn,that is, by varying the air pressure in the chamber156. An increase inair pressure tends to move the supporting element 28 in the clockwise.direction, thus increasing the air pressure in the cylinder 24 andincreasing the tension in the strandof yarn. Similarly, a decrease inair pressure tends to permit the supporting element 20 to move in thecounterclockwise direction, thus decreasing the air pressure in thecylinder-'24 anddecreasing the tension in the strand of yarn. Thustheten sion in the strand of yarn is a direct function of the airpressure in the chamber 56.- The supporting element 20 remainssubstantially vertical at all times, its position being changed onlyminutely to provide variations in the amount of restriction of the airflowing from the bleed orifice 82. 'It is additionally subject to minormovements resulting from minor variations in yarn tension, which minorvariations are immediately corrected in the manneralready described;

As already stated, the strand of yarn in passing between the Washers I6and 18 causes them'to rotate, but such rotation is retarded by thfriction applied to the washer l6 by the friction disc 38. Both of theWashers l6 and 18 are loosely mounted, and they can readily tilt whennecessary to permit a knot in the yarn to pass between them withoutmaterially affecting the amount of tension applied to the yarn. Thelower washer I8 has a depending skirt which'te'nds to prevent dust andlint from entering the casing through theopening 2L, The entry of dustand lint is further prevented by reason of the fact thatair is escapingpast the piston 22 and fromthe bleed. orifice 82 into the interior ofthe casing 18. This causes a flow of air outward through the opening 2|and this outward fiow prevents the inward movement of dust and lint.

The strand of yarn 36 may have some primary tension therein beforereaching the friction washers l6 and I8 and the means for guidin thestrand of yarn to the friction means is so located as toavoid anytendency for the said primary tension in the yarn to cause bodilymovement of the friction means, that is, pivotal movement about the axisof the pivot pin 40. Preferably,

and as shown, the strandof yarn is guided to the friction washers in adirection approximately perpendicular to the direction of bodily or'pivotal movement. Some primary tension is usually desirably so long asit is less than the minimum tension required in the strand after itpasses the friction washers- One reason for providing primary tension isthat it overcomes the tendency, which otherwisefrequently exists, forthe strand of yarn to be guided outward by the washers l6 and I8 so thatit is near the peripherie of the washers and out of engagement with thesleeve 26. I'preferably provide a primary tension means of suitableconstruction, such a means being shown in Fig. 4 and also in Fig. 8..The housing [0 carries a bracket 84 provided with a vertical. pivot pin86 on which are mounted two rotatable washers 88 and 98 between whichthe strand of yarn passes. The weight of the upper Washer 88 serves totension the yarn. The strand of yarn,

is guided to the washers 88 and 98 by means of an eye 92 on thebracket84. The eye 92prevents the transmission to the primary tension members.

of any whipping or whirling action resulting from unwinding,

There is a tendency for the mechanism as thus far described to asomewhat unstable. In other words, there is a tendency toward selfexcited oscillation or vibration of the pivoted element 20 with theparts carried thereby, such a tendency being inherent in any freelymovable member subject to normally equal opposed forces, one of whichmay be subject to minor variations which are automatically corrected. Inorder to prevent such oscillation or vibration means is provided forinsuring a lag in the change ofair pressure in the cylinder 24 as theresult of a change in yarn tension. A relatively large air reservoir 94is provided, preferably in the bottom of the casing I0, this reservoirbeing closed at the rear by a plate 95, and the flexible tube 16 isconnected with a rigid tube 96 extending into the reservoir. Air issupplied to the reservoir 94 through a control member 98 with which isconnected an air supply conduit I00. The control member 98 has adiaphragm I02 therein having an orifice I04 of small diameter. FiltersI01 are preferably also provided. The orifice I 04 is just large enoughto pass enough air to make up for leakage past the piston 22 and for airflow through the bleed orifice 82 when the unit is operating at maximumyarn tension. The pressure in the air supply conduit I is maintained atsuch an amount, above a critical amount, that the rate of air flow intothe reservoir is constant.

With this arrangement, and on account of the flow of air into therelatively large reservoir 94 at a constant rate, the pressure withinthe cylinder 24 is increased or decreased relatively slowly as the flowof air at the bleed orifice is decreased or increased as the result ofchanges in yarn tension. Thus, when the equilibrium is destroyed throughchanges in yarn tension, the said equilibrium is restored relativelyslowly without exciting oscillation or vibration of the supportingelement 20 and the parts carried thereby. With this arrangement pressurewithin the cylinder 24 is increased relatively slowly as the rate offlow through the bleed orifice is decreased. Thus, when the equilibriumis destroyed through an increase in yarn tension, the said equilibriumis restored relatively slowly without exciting an oscillation orvibration of the supporting element 20 and the parts carried thereby.While there is a lag in the response of air pressure changes in thecylinder 24 to changes in yarn tension, such lag is very small and maybe only a fraction of a second, but it is suflicient to preventundesirable oscillation or vibration.

The supporting element 20 carries near its lower end a relatively largeweight I08 which is adjustable in position and is held in place by meansof a set screw I I 0. The weight I08 serves to counterbalance thefriction washers and other parts carried by the element 20, so that thecenter of gravity of all of the pivotally movable parts is at or nearthe pivotal axis. With the center of gravity at the said axis, there isno tendency for the parts to oscillate as the result of vibration in thesupporting framework on which the unit may be mounted. Under someconditions it may be desirable to so adjust the weight that the centerof gravity is somewhat below the pivotal axis, the weight thus tendingto hold the parts in their central upright positions. Under otherconditions, the weight may be adjusted to bring the center of gravityslightly above the pivotal axis, thus providing extreme sensitivity ofcontrol when a very small yarn tension is required.

- Ordinarily, yarn tensloning units such as described are used forcontrolling the tension of a large number of strands of yarn which arebeing wound onto a rotatable beam or other equivalent device. As many as1,000 such units may be included in a single installation. Fig. 8 is adiagrammatic view showing three units suitably mounted, these beingsupported on a suitable creel which is not shown. It will be understoodthat this view is merely illustrative and that a much larger number ofunits is ordinarily provided. The strands of yarn 36, 36 are unwoundfrom suitably supported supply packages, such as cones I I2, I I2, andeach strand is guided through the corresponding eye 92, between theprimary friction washers 88 and 90, thence between the friction washersI6 and I8, and finally to the beam on which they are to be wound.

A main operating air conduit H4 is provided with which the severalbranch operating conduits I00, I00 are connected. A second maincontrolling air conduit I I6 is provided with which the several branchcontrolling conduits I0, I0 are connected. An air compressor I I8 isprovided, air flowing to the compressor through a filter I20 and flowingfrom the compressor through a relief valve I22. The main air conduits H4and H6 are connected beyond the relief valve I22.

A manually adjustable pressure regulator I24 is connected in the maincontrolling air conduit I I6, this serving to maintain the pressureconstant notwithstanding any variations in the pressure of the airdelivered thereto. The pressure regulator can be adjusted to providedifferent constant pressures. The said main controlling air conduit II6preferably has a relief valve I28 connected therein. Also connected withthe main air conduit H6 is a pressure gage I 28.

It has already been stated that an equilibrium is maintained in eachunit between the tension in the corresponding strand of yarn and thepressure in the air chamber 56. The yarn tension can be increased ordecreased at all of the units by varying the air pressure in the severalchambers 56, this being done by adjusting the pressure regulator I 24.Inasmuch as the said chambers 56 of all of the units are connected withthe same main controlling air conduit IIG, it will be seen that thepressure in all of the chambers 56 can be changed simultaneously anduniformly, thus changing the tension in all of the strands of yarnsimultaneously and uniformly. The pressure gage I28 can be calibrated toread directly in units of yarn tension such as grams. Thus, by observingthe gage I28 and by adjusting the regulator I24 the operator canprovide, within the limits of the apparatus, any desired yarn tension inall of the strands. This ready adjustment of the yarn tension at all ofthe units simultaneously and uniformly is in contrast with the existingconventional practice of individually adjusting or changing all of thevery large number of tension regulator units that must be included inone installation.

An apparatus embodying the invention is adapted for use with a widevariety of yarns,

and with suitable adaptations as to details of construction it may beused for materials not ordinarily designated as yarn, such as wires.narrow fabrics and the like. Irrespective of the kind of yarn or othermaterial, the tension is very accurately controlled, this being effectedeven though there are wide variations in operating conditions.Notwithstanding changes in the manner of unwinding from the package, orchanges in the primary tension, or variations in the size of the yarn"or variations in the condition of the yarn due to humidity changes orotherwise, the tension remains substantially'eonstant. The apparatusis pl jfi l a y's for use with elastic yarn wherein the "tension must bekeptat practically zero, value to'avoid undue stretching and elongation;f

A very important advantage of the" apparatus is the provision formaintaining the same tension in a large number of strands of yarnand theprovision for changing the tension in all of the strands of yarnsimultaneously and uniformly. Inasmuchas the various'units oftheapparatus are exact duplicates of eachjother, the tension appliedby'them totheir respective strands oi yarn is adirectiunction oj'rthepressure of the controlling fluid; this pressure being exactly the samein all of the'unitsfand being subject to changes uniformly affecting allof the units.

What I claim is: a

1. The combination in a tension regulatorflf'or a moving strand of yarn,of means for resisting the movement of the'yarn tojcauseitension theretothe fluid actuated means, means dependent on the tension in the yarnafter passing the said friction members for varying the pressure of thefluidsuppliedlto the fluid actuated means to so actuated means carriedby the supporting ele in, fluid actuated means acting 0 1' the resistingmeans to cause the latter to apply resistance to the yarn, means forsupplyingffluid under pressureto'thesaid fluid actuated means, and meansdependent on the tension'in the yarnjafter' passing the said resistingmeans for varying the pressure Of the'fluid supplied by thefluidsupplying means to the fluid actuated means'to maintain the saidyarn tension substantially constant.

2. The combinationin a tension regulator for a moving strand of"y'arn ofrelatively-movable friction washers between which "the yam passes, thesaid Washers being rotatable about substantially common axes undertheinfluence ofthe moving yarn, fluid actuated nie'ansiactingon one of thewashers to press it toward the otherwasher and thereby frictionallyresist-- the movement of the yarn and cause'tensiontherein, and meansdependent on the tension in the yarn after passing the saidfrictionw'ashers for varying the pressure exerted by the fluid actuatedmeans inversely in accordance vvith-=var-iations inthe said tension. I a

3. In a tension regulator fora moving strand of yarn, the combination of:a first friction member, a second friction member'movable toward andfrom the first frictionmember, fluid actuated means, comprisinga-pistonsand a cylinder one of which is .movablerelativelyto the otherwith the movable one of the :last said elements.

acting on the second friction member to press it toward the firstfriction member. to engagethe yarn between the said membersa d t er bcause tension in the va nimeans for supplyi fluid to t e id actuate mansiand m ans,

dependent on the tension in the yarn after passing the said frictionmembers for varying the pressure of the fluid suppliedto the fluid actuQated means to so vary theipressure on the second friction member as tomaintain the yarntension' substantially constant. I I l. 4. In atension-regulator for a moving-strand of yarn, the combination of afirst friction mem ber, a second frictionimember movable toward and fromthe first friction mehlberQfluid actuated means comprising .a pistonand. ja cylinderone of which is movable rela'tivelyfto the. other with"the movable one of the'la'stfsaid elements acting on the second frictionmember "to press it toward the first ,fric'tionmemberto"engagethe yarnbetween the said members and thereby causetension inthe'yarn, means'forsupplying fluid vary the pressure on the second friction member asjtomaintain the yarn tensionsubstantially constant, and means for varyingthe action of the tension dependent means to vary the amount of the saidsubstantially constant tension. a 5. In a tension regulator for a movingstrand of yarn, the combination of'a supporting element,

a first friction washer carried by the supporting 7 element androtatable about a vertical axis, fluid ated means and being movablethereby toward the first friction iwasher'jto engage the yarn betweenthe saidfwashers and thereby cause tension in the yarn, means forsupplying fluidlunder pressure to the interior of the cylinder, and

means dependenton thetension in the yarn after passing the saidtrictioln washers forvarying the pressure of, the fluid supplied'to thecylinderto so vary the pressure on, the second friction washer as tomaintain the yarntension V substantially constant.

6. In'a tension regulatorfor a moving strand of yarn, the combination ofajsupporting ele' ment, a first friction washer carried by thesupporting element, the said Washer being rotatable elet v lv oth sugp ri em nt a t a v rtical axis but being'adjustable relatively to, the

sa d el e toroiate. a uts t l d axis, u actuated means carried by thesupporting element and :GQH Pl S I a e t al Pi n, n a ver cal i. er withone of th mm le t c lly relatively toathe. w n. a s c nd f t o weshrhelow th first irict iw h h i second washer being'rotatable relativelyto the supporting element'about the same vertical axis as thefirstwasher but being adjustable relatively to the said element to rotateabout a tilted axis: and the said second Washer being carried by thevertically movable element of the fluid actuated means and being movablethereby'toward the first friction washerto engage the yarn between thesaid washers and thereby cause tension in-theyarn, means for supplyingfluid under pressure to the interior .of the cylinder, and meansdependent on thetension in the yarn after. passing :the'said frictionwashers for varying the-pressure of the fluid supplied to the cylinderto sovaryithe pressure on the second friction washer as to maintain theyarn tension substantially constant.

- -7. Ina-tension regulator-fora moving strand of yarn, the combinationof aasupporting element, two companion friction; washers on, thesupporting element rotatable about ;a vertical axis undertheinfluencevof a, strand of yarn pass.-

ing between them, a vertical piston on the supporting element heldagainst. vertical movement, r

a vertical cylinder closedat the top and enclosing the piston andvertically movable relatively thereto, the said cylinder'gupon upward-move.-'

ment engaging the lower friction washer to move it toward the upperfriction washer .so. asv to en-' gage the yarn' between the said:washers and thereby cause tension' in the -yarn' and the said cylinderhaving an upward extending concentric sleeve on which the lower washeris rotatable and which is engaged by the yarn so that the said sleeveand cylinder are rotated with respect to the piston, means for supplyingair under pressure to the interior of the cylinder, and means dependenton the tension in the yarn after passing the said friction washers forvarying the pressure of the air supplied to the cylinder to so vary thepressure on the second friction washer as to maintain the yarn tensionsubstantially constant.

8. In a tension regulator for a moving strand of yarn, the combinationof means for resisting the movement of the yarn to cause tensiontherein, fluid pressure actuated means acting on the resisting means tovary the resistance applied thereby to the yarn, a conduit serving tosupply fluid under pressure to the fluid pressure actuated means andhaving a bleed orifice therein, and means dependent on the tension inthe yarn after passing the said resisting means for varying the flow offluid through the bleed orifice to thereby vary the pressure of thefluid supplied to the fluid pressure actuated means so as to maintainthe yarn tension substantially constant.

9. In a tension regulator for a moving strand of yarn, the combinationof a first friction member, a second friction member movable toward andfrom the first friction member, fluid pressure actuated means comprisinga piston and a cylinder one of which is movable relatively to the otherwith the movable element acting on the second friction member to pressit toward the first friction member to engage the yarn between the saidmembers and thereby cause tension in the yarn, a conduit serving tosupply fluid under pressure to the fluid pressure actuated means andhaving a bleed orifice therein, and means dependent on the tension inthe yarn after passing the said friction members for varying the flow offluid through the bleed orifice to thereby vary the pressure on thesecond friction member so as to maintain the yarn tension substantiallyconstant.

10. In a. tension regulator for a moving strand of yarn, the combinationof means for frictionally engaging the yarn to resist the movementthereof, pneumatically actuated means acting on the friction means tovary the friction applied thereby to the yarn, a conduit serving tosupply air under pressure to the pneumatically actuated means and havinga bleed orifice therein, means dependent on the tension in the yarnafter passing the said friction means for varying the flow of airthrough the bleed orifice to thereby vary the action of thepneumatically actuated means on the friction means so as to maintain theyarn tension substantially constant, and means for varying the action ofthe tension dependent means to decrease or increase the amount ofbleeding and thereby increase or decrease the tension in the yarn.

11. In a tension regulator unit for a moving strand of yarn, thecombination of means for frictionally engaging the yarn to resist themovement thereof and to thereby cause tension therein, pneumaticallyactuated means acting on the friction means to vary the friction appliedthereby to the yarn, an air reservoir within the unit, a conduit servingto supply air under pressure from the reservoir to the pneumaticallyactuated means and having a bleed orifice therein, and means dependenton the tension-in the yarn after passing the said friction means forvarying 12 the flow of air through the bleed orifice to there= by varythe action of the pneumatically actuated means on the friction means soas to maintain the yarn tension substantially constant.

12. In a tension regulator unit for a moving strand of yarn, thecombination of means for frictionally engaging the yarn to resist themovement thereof and thereby cause tension therein, pneumaticallyactuated means acting on the friction means to vary the friction appliedthereby to the yarn, an air reservoir within the unit, means forsupplying air at a constant rate to the reservoir, a conduit serving tosupply air under pressure from the reservoir to the pneumaticallyactuated means and having a bleed orifice therein, and means dependenton the tension in the yarn after passing the said friction means forvarying the flow of air through the bleed orifice to thereby vary theaction of the pneumatically actuated means on the friction means so asto maintain the yarn tension substantially constant.

13. A tension regulator for a moving strand of yarn comprising incombination, a resisting means bodily movable in its entirety andengaging the yarn forresisting the movement thereof so as to causetension therein, the tension in the yarn moving from the resisting meanstending to bodily move it in one direction, a constant pressure means.tending to bodily move the resisting means in the opposite direction,the said constant pressure means tending in conjunction with the yarntension to maintain the resisting means in a position of equilibriumwherein the yarn tension is constant, means associated with the saidresisting means for varying the resistance thereof, and means separatefrom the constant pressure means and dependent on bodily movements ofthe resisting means out of its said position of equilibrium for causingthe said resistance varying means to decrease the resistance of theresistance means when it moves as aforesaid in the direction of yarnmovement and to increase the resistance of the said resistance meanswhen it moves as aforesaid in the opposite direction so as to therebymaintain the said yarn tension substantially constant.

14. A tension regulator for a moving strand of yarn comprising incombination, a means bodily movable in its entirety and engaging theyarn for resisting the movement thereof so as to cause tension therein,the tension in the yarn moving from the resisting means tending tobodily move it in one direction, a, constant pressure means tending tobodily move the resisting means in the opposite direction, the saidconstant pressure means tending in conjunction with the yarn tension tomaintain the resisting means in a position of equilibrium wherein theyarn tension is constant, means associated with the said resisting meansfor varying the resistance thereof, means separate from the constantpressure means and dependent on bodily movements of the resisting meansout of its said position of equilibrium for causing the said resistancevarying means to decrease the resistance of the resistance means when itmoves as aforesaid in the direction of yarn movement and to increase theresistance of the said resistance means when it moves as aforesaid inthe opposite direction so as to thereby maintain the said yarn tensionsubstantially constant, and means for changing the force exerted by theconstant pressure means to thereby establish a new position ofequilibrium ang l tion means in the opposite direction,.means-forguiding the yarn to the friction means in a direction substantiallyperpendicular to the direc-' tion of bodily movement ofthefriction meansso as to avoidany tendency for primary tension in the said yarn tobodily move the friction means, andmeans separatefrom the constantpressure means anddependent on thebodily movements of the friction meansunder the influence of yarn tension and under the influence of the saidcon- A stant pressure means for varying the action of the said frictionmeansso as to maintain the said yarn tension substantially constant.

. 1,6. A, tension regulator for amoving strand of yarn comprisinginicombination, a bodily movable friction means engagingv the yarn andresisting the movement thereof so as to cause ten-' sion therein, thesaidfriction means being bodily movable in one direction undertheinfluence of the tension in the yarn-moving therefrom, a con- U stantpressure meansfor bodily moving the friction means in the oppositedirection, fluid pressure means separate from the constant. pressuremeans acting on the friction means to vary the, resistance appliedtherebyv to the yarn, andv means dependent on bodily movementsof thefriction means under the influence of yarn tension and under theinfluence of the said constant pressure means for causing the said fluidDIES-f sureqmeans to vary the action of the said friction means so as tomaintain the said yarn tension substantially constant.

17.. A yarn tension regulator for a moving strand: of yarn comprising,in combination, a bodily movable friction means comprising a firstfrictionmember and a second friction member movable, toward and from thefirst friction member, means supporting the said friction means forbodily movement in one direction under the influence of the tension inthe yarn moving.

therefrom, a constant pressure means for bodily moving the frictionmeansin the opposite direction, fluid pressure'meansseparate from theconstant pressure means and comprising a piston and a. cylinder oneofwhich is movable relatively totheother withthe movable element connectedwith the second friction member to press it toward the first frictionmember to engage the yarn and cause tension therein, means forsupplying'fluid underpressure to the interior of the cylinder, and meansdependent onbodily movements of the friction mean under the influence of1 yarn tension and under the influence of the said-i constant pressuremeans for causing the said fluid pressure means to vary the actionof thesaid frictionmeans so as to maintain the said yarn tension substantiallyconstant. 7

18. A tension regulator for a-moving strand of yarn comprising incombination, a friction means engaging the yarn and resisting themovement thereof so as to cause tension therein, means supporting thesaid friction means for bodily movement in one direction under theinfluence of the tension in the yarnmoving therefrom, a constantpressure means for bodily moving the friction means in the'oppositedirection, a fluid pressure means separate from the constant'pressuremeans acting on the friction means to vary the resistance appliedthereby to the yarn, aconduit serving to supply fluid to thefluidpressure means and having a bleed orifice therein, and means dependenton bodily movements of the friction means under theinfluence of yarntension and under the influence of the said constant pressure means forvarying the flow of fluid through the blee'dorifice to thereby cause thesaid fluid pressure mean to vary the action of the saidfriction means"so as to maintain the said yarn tension substantially constant. i

19.: A tension: regulator unit for a moving strand of yarn comprising incombination, a fric tion means engaging theyarnand resisting themovement thereof goes to cause tension therein, means supporting thesaid friction means for bodily movement in one direction under theinfluence of the tensionin the yarn moving there-z from, aconstantpressure means for bodily moving the friction means in the :oppositedirection, a pneum'aticmeans separate from the constant.

pressure means acting on the friction'mean to vary the resistanceapplied thereby to the yarn, I

an air reservoir Within the unit,means forsup plying air to thereservoir atia constantirate, a conduit serving to supply air from thereservoir to the pneumatic means and having a bleed orilice therein, andmeans dependent on bodily movements of the friction means under. the mefluence of yarn tension and under the influence of the said constantpressure means for varying the flow of air through the bleed orifice tothereby cause the said pneumatic means to vary the action of the saidfriction means :so as to'main-i tain the said yarn tension substantiallyconstant.

ing the friction means in the opposite direction,

a pneumatic means separate from the" constant pressure means acting: onthe friction means to vary the resistanceapplied thereby to the yarn, aconduit serving to supply air to the pneumatic means and having a bleedorifice therein, an element adjacent the bleed orifice for restrictingthe flow of air therethrough, and means de-.

pendent on bodily movements of the friction means under the influenceofyarn tension and under the influence of the said constant. pres-: suremeans for varying'the distance between the bleed orifice and the fiowrestricting elementto vary the flow of air through the. bleedxiorificeto thereby cause the said pneumatic means to vary the action of the saidfriction means so as to maintain the said yarn tension substantiallyconstant. a r

21. A tensionregulator for a moving strand of yarn'comprising incombination, a friction means for resisting the movement of the yarn tocause:-

tension thereimmeans forsupporting the fric-- tion means forpivotalmovement about an axisv spaced from the line of movement of the yarn.from the friction means and perpendicular to a vertical plane'throughthe said line, the said sup-- porting means permitting the frictionmeans to pivotally move in one direction under the .influ-' ence of thetension in theyarn movingthere-- from, a constant pressure means forpivotally moving the friction means in the opposite direction, and meansseparate from the constant pressure means and dependent on the pivotalmovements of the friction means under the influence of yarn tension andunder the influence of the said constant pressure means for varying theaction of the said friction means so as to maintain the said yarntension substantially constant.

22. A tension regulator for a moving strand of yarn comprising incombination, a friction means for resisting the movement of the yarn tocause tension therein, means for supporting the friction means forpivotal movement about an axis spaced from the line of movement of theyarn from the friction means and perpendicular to a verticalplanethrough the said line, the said supporting means permitting thefriction means to pivotally move in one direction under the influence ofthe tension in the yarn moving therefrom, a constant pressure means forpivotally moving the friction means in the opposite direction, meansassociated with the said friction means for varying the frictionthereof, means for guiding the yarn to the friction means in a directionsubstantially parallel to the axis of pivotal movement of the saidfriction means so as to avoid any tendency for the primary tension inthe said yarn to pivotally move the friction means, and means separatefrom the constant pressure means and dependent on the pivotal movementsof the friction means under the influence of yarn tension and under theinfluence of the said constant pressure means for causing the saidfriction varying means to decrease the friction of the friction meanswhen it moves as aforesaid in the direction of yarn movement and toincrease the friction of the said friction means when it moves asaforesaid in the opposite direction so as to maintain the said yarntension substantially constant.

23. A tension regulator for a moving strand of yarn comprising incombination, a friction means for resisting the movement of the yarn tocause tension therein, means for supporting the friction means forpivotal movement about an axis spaced from the line of movement of theyarn from the friction means and perpendicular to a vertical planethrough the said line, the said supporting means permitting the frictionmeans to pivotally move in one direction under the influence of thetension in the yarn moving therefrom. a constant pressure means forpivotally moving the friction means in the opposite direction, fluidpressure means separate from the constant pressure means and carried bythe supporting means and movable with the friction means, the said fluidpressure means acting on the friction means to vary the resistanceapplied thereby to the yarn, and means dependent on the pivotalmovements of the friction means under the influence of yarn tension andunder the influence of the said constant pressure means for causing thesaid fluid pressure means to vary the action of the said friction meansso as to maintain the said yarn tension substantially constant.

24. In a tension regulator for a moving strand of yarn, the combinationof a friction means bodily movable in its entirety and engaging the yarnfor resisting the movement thereof so as to cause tension therein, thesaid friction means being bodily movable in one direction under theinfluence of the tension in the yarn moving therefrom, means forapplying constant fluid pressure tending to bodily move the frictionmeans in the opposite direction, means associated with the said frictionmeans for varying the friction thereof, and means separate from theconstant fluid pressure means and dependent on the bodily movements ofthe friction means for causing the said friction varying means todecrease the friction of the friction means when it moves as aforesaidin the direction of yarn movement and to increase the friction of thesaid friction mean when it moves as aforesaid in the opposite directionso as to maintain the said yarn tension substantially constant.

25. In a tension regulator for a moving strand of yarn, the combinationof a friction means bodily movable in its entirety and engaging the yarnfor resisting the movement thereof so as to cause tension therein, thesaid friction means being bodily movable in one direction under theinfluence of the tension in the yarn moving therefrom, a chamber closedby a flexible diaphragm, means for maintaining a constant fluid pressurewithin the chamber, means connected with the bodily movable frictionmeans and engaging the diaphragm whereby the fluid pressure within thechamber tends to bodily move the friction means in the oppositedirection, means associated with the said friction means for varying thefriction thereof, and means separate from the constant fluid pressuremeans and dependent on the bodily movements of the friction means forcausing the said friction varying means to decrease the friction of thefriction means when it moves as aforesaid in the direction of yarnmovement and to increase the friction of the said friction means when itmoves as aforesaid in the opposite direction so as to maintain the saidyarn tensionsubstantially constant.

26. In a tension regulator for a moving strand of yarn, the combinationof a friction means bodily movable in its entirety and engaging the yarnfor resisting the movement thereof so as to cause tension therein, thetension in the yarn moving from the friction means tending to move it inone direction, a means for applying normally constant fluid pressuretending to bodily move the friction means in the opposite direction, thesaid constant fluid pressure means tending in conjunction with the yarntension to maintain the friction means in a position of equilibriumwherein the yarn tension is constant, means associated with the saidfriction means for varying the friction thereof, means separate from theconstant fluid pressure means and dependent on bodily movements of thefriction means out of its said position of equilibrium for causing thesaid friction varying means to decrease the friction of the frictionmeans when it moves as aforesaid in the direction of yarn movement andto increase the friction of the said friction means when it moves asaforesaid in the opposite direction so as to maintain the said yarntension substantially constant, and means for changing the pressureexerted by the constant fluid pressure means to thereby establish a newposition of equilibrium and thus change the said substantially constantyarn tension.

27. In a tension regulator for a moving strand of yarn, the combinationof a bodily movable friction means engaging the yarn and resisting themovement thereof so as to cause tension therein, the said friction meansbeing bodily movable in one direction under the influence of the tensionin the yarn moving therefrom, a means a vertical plane therethrough, thesaid washers and the supporting element being pivotally movable in onedirection under the influence of yarn tension, a pneumatic pressuremeans on the supporting element below the washers and comprising apiston and a cylinder one of which is movable relatively to the other topress the lower washer toward the upper washer and thereby applyfrictional resistance to the yarn, a chamber within the housing closedby a flexible diaphragm, means for supplying fluid under pressure to thechamber, means on the supporting element engaging the diaphragm toenable the diaphragm to cause pivotal movement of the supporting elementand of the parts carried thereby in the direction opposite to thedirection in which they move under the influence of yarn tension, aconduit for supplying air to the pneumatic pressure means, the saidconduit having a flexible portion permitting the said pneumatic pressuremeans to move with the supporting element and the said conduit having astationary bleed orifice, and means on the supporting elementimmediately adjacent the bleed orifice for restricting the flow of airtherefrom, the said last means being mov- I able away from the orificeto permit increased flow therefrom when the supporting member is movedin one direction by increased yarn tension and the last said means beingmovable toward the orifice to cause decreased flow therefrom when thesupporting member is moved in the opposite direction as the result ofdecreased yarn tension.

33. The combination in a tension regulator for a moving strand of yarn,of a casing, a supporting element pivoted within the casing for movementabout a horizontal axis and projecting therefrom at the top, twofriction washers carried by the supporting element at the top thereofabove the casing and freely rotatable about a normally vertical axis,the said washers being adapted to receive between them a strand of yarnmoving therefrom in a line spaced from the pivotal axis of thesupporting element and perpendicular to a vertical plane therethrough,the said washers and the supporting element being pivotally movable inone direction under the influence of yarn tension, a primary tensionmeans carried by the casing and positioned so that the strand of yarnmoves therefrom to the friction washers in a direction parallel to thepivotal axis of the supporting element, a pneumatic pressure means onthe supporting element below the washers and comprising a piston and acylinder one of which is movable relatively to the other to press thelower washer toward the upper washer and thereby apply frictionalresistance to the yarn, a constant pressure means tending to causepivotal movement of the supporting element and of the parts carriedthereby in the direction opposite to the direction in which they moveunder the influence of yarn tension, a conduit for supplying air to thepneumatic pressure means, the said conduit having a flexible portionpermitting the said pneumatic pressure means to move with the supportingelement and the said conduit having a stationary bleed orifice, andmeans on the supporting element immediately adjacent the bleed orificefor restricting the flow of air therefrom, the said last means beingmovable away from the orifice to permit increased flow therefrom whenthe supporting member is moved in one direction by increased yarntension and the last said means being movable toward the orifice tocause decreased fiow therefrom when the sup- 20 porting member is movedin the opposite direction as the result of decreased yarn tension.

34. The combination in a tension regulator for a moving strand of yarn,of a casing, a supporting element pivoted within the casing for movementabout a horizontal axis and projecting therefrom at the top, twofriction washers carried by the supporting element at the top thereofabove the casing and freely rotatable about a normally vertical axis,the said washers being adapted to receive between them a strand of yarnmoving therefrom in a line spaced from the pivotal axis of thesupporting element and perpendicular to a vertical plane therethrough,the said washers and the supporting element being pivotally movable inone direction under the influence of yarn tension, a fluid pressuremeans on the supporting element below the washers and comprising apiston and a cylinder one of which is movable relatively to the other topress the lower washer toward the upper washer and thereby applyfrictional resistance to the yarn, a flexible conduit for supplyingfluid to the fluid pressure means, a constant pressure means tending tocause pivotal movement of the supporting element and of the partscarried thereby in the direction opposite to that in which they moveunder the influence of yarn tension, means dependent on the pivotalmovements of the friction means under the influence of yarn tension andunder the influence of the pneumatic pressure means for causing thefluid pressure means to vary the action of the said friction means so asto maintain the said yam tension substantially constant, and a weightcarried by the supporting element at a position near the bottom thereofwithin the casing and spaced downward from the pivotal axis, the saidweight serving to counterbalance the friction washers and other partscarried by the supporting element.

35. The combination in a tension regulator for a moving strand of yarn,of a casing, a. supporting element pivoted within the casing formovement about a horizontal axis and projecting therefrom at the top,two friction washers carried by the supporting element at the topthereof above the casing and freely rotatable about a normally verticalaxis, the said washers being adapted to receive between them a strand ofyarn moving therefrom in a line spaced from the pivotal axis of thesupporting element and perpendicular to a vertical plane therethrough,the said washers and the supporting element being pivotally movable inone direction under the influence of yarn tension, a pneumatic pressuremeans on the supporting element below the washers and comprising apiston and a cylinder one of which is movable relatively to the other topress the lower washer toward the upper washer and thereby applyfrictional resistance to the yarn, a flexible conduit for supplying airto the pneumatic pressure means, a constant pressure means tending tocause pivotal movement of the supporting element and of the partscarried thereby in the direction opposite to that in which they moveunder the influence of yarn tension, means dependent on the pivotalmovements of the friction means under the influence of yarn tension andunder the influence of the constant pressure means for causing thepneumatic pressure means to vary the action of the said friction meansso as to maintain the said yarn tension substantially constant, and aweight carried by the supporting element at a position near the bottomthereof within the casing and spaced down- 21 ward fromthezpivotaleaxis; thesaid weight being adapted to counterbalance. thefriction washers and otherparts carried bythe supportingelement and thesaidweight beingadjustable outiof its counterbalaricing position.

36. In an apparatus for regulating the tension in a: plurality ofmoving.- strands of yarn, the combination of a plurality ofsimilar'units for resisting the movements of the respective strands tocause tension therein, each unit including means for maintaining thetension in the correspondin strand of yarn substantially constant andalso including fluid pressure operable means for increasing ordecreasing the said tension, and

a common means connected with all of the units for simultaneously anduniformly changing the fluid pressure in the fluid pressure operablemeans of all of the said units to increase or decrease the tension inall of the said strands of yarn simultaneously and uniformly.

37. In an apparatus for regulating the tension in a plurality of movingstrands of yarn, the combination of a plurality of similar units forresisting the movement of the respective strands to cause tensiontherein, each unit including means for maintaining the tension in thecorresponding strand of yarn substantially constant and also includingfluid pressure operable means additional to the first said means forincreasing or decreasing the said tension, a source of fluid under pressure, a main fluid conduit leading from the said source, branch fluidconduits leading from the main conduit to the several units, meansconnected in the main fluid conduit for maintaining constant pressuretherein and in the branch conduits and in the fluid pressure operablemeans of the several units, and means for changing the said constantfluid pressure to thereby change the pressure in the fluid pressureoperable means of all of the several units simultaneously and uniformlyso as to increase or decrease the tension in all of the said strands ofyarn simultaneously and uniformly.

38. In an apparatus for regulatin the tension in a plurality of movingstrands of yarn, the combination of a plurality of units for regulatingthe tension in the respective strands of yarn, each unit including meansfor frictionally engaging the yarn to resist the movement thereof andthereby cause tension therein, including an operating fluid pressuremeans acting on the friction means to vary the friction applied therebyto the yarn, including means dependent on the tension in the yarn afterpassing the friction means for causing the operating fluid pressuremeans to so vary the action of the friction means as to maintain thesaid yarn tension substantially constant and including a controllingmeans dependent on fluid pressure for adjusting the action of the saidoperating fluid pressure means to provide increased or decreasedtension, and a common means connected with all of the units forsimultaneously and uniformly changing the fluid pressure in the saidcontrolling means of all of the units to increase or decrease thetension in all of the said strands of yarn simultaneously and uniformly.

39. In an apparatus for regulating the tension in a plurality of movingstrands of yarn, the combination of a plurality of units for regulatingthe tension in the respective strands of yarn, each unit including meansfor frictionally engaging the yarn to resist the movement thereof andthereby cause tension therein, including an operating fluid pressuremeans acting on the friction means to vary the friction applied therebyto 1the yarn inc1uding means dependent on :the-,-ten- .sion; in the Jam:after Passingthe :friction means foncau sing theioperating fluidpressuremeans to so vary:-the .action;,ofthe friction means as tomaintaimthasaid yarntension substantially constant andincluding :acontrolling-means dependent on;fluid;pres sure foradjustin the ,actionof the saidloperatingi-fluid pressure means to provide the saidoperating fluidmressure means of the several .,units,, a ,maincontrolling conduit leading'from' the said source, branch conduitsleading from the said main controlling cond'uit'to" the said fluidpressure controlling means of the several units, means connected in themain controlling conduit for maintaining constant pressure therein andin the corresponding branch conduits and in the said controlling fluidpressure means of the several units, and means for changing the lastsaid constant pressure to thereby change the pressure in the saidcontrolling fluid pressure means of the several units so as to vary thetension in all of the strands of yarn simultaneously and uniformly.

' 40. In an apparatus for regulating the tension in a plurality ofmoving strands of yarn, the combination of a plurality of units forregulating the tension in the respective strands of yarn, each unitincluding means for frictionally engaging the yarn to resist movementthereof so as to cause tension therein which friction means is bodilymovable in its entirely in one direction under the influence of thetension in the yarn moving therefrom, including a constant fluidpressure means for bodily moving the friction means in the oppositedirection, including means associated with the friction means forvarying the friction thereof and also including means separate from theconstant fluid pressure means and dependent on bodily movements of thefriction-means for causing the said friction varying means to decreasethe friction of the friction means when it moves as aforesaid in thedirection of yarn movement and to increase the friction of the saidfriction means when it moves as aforesaid in the opposite direction soas to maintain the said yarn tension substantially constant, and acommon connected with all of the units for simultaneously and uniformlychanging the pressure in the said constant fluid pressure means of allof the units to increase or decrease the tension in all of the saidstrands of yarn simultaneously and uniformly.

41. In an apparatus for regulating the tension in a plurality of movingstrands of yarn, the combination of a plurality of units for regulatingthe tension in the respective strands of yarn, each unit including meansfor frictionally engaging the yarn to resist the movement thereof andthereby cause tension therein which friction means is bodily movable inone direction, under the influence of the tension in the yarn movingtherefrom, including controlling means dependent on constant fluidpressure for bodily moving the friction means in the opposite direction,including an operating fluid pressure means separate from the constantfluid pressure controlling means and acting on the friction means tovary the friction applied thereby to the yarn and including meansdependent on bodily movements of the friction means under the influenceof yarn tension and under the influence of the said con- 23 stant fluidpressure controlling means for causing the operating fluid pressuremeans to vary the action of the said friction means so as to maintainthe said tension substantially constant, and

Number a common means connected with all of the units 5 forsimultaneously and uniformly changing the pressure in the said constantpressure controlling means of all of the said units to increase ordecrease the tension in all of the said strands of yarn simultaneouslyand uniformly,

PAUL J. CAMPBELL.

REFERENCES CITED The following references are of record in the file ofthis patent:

Number 24 UNITED STATES PATENTS Name 7 Date Murdock Nov. 27, 1923Carpenter May 26, 1925 FOREIGN PATENTS Country Date Great Britain Apr.9, 1931 Great Britain June 18, 1931

